There are many applications, primarily industrial applications, where a vacuum system is used to hold semiconductor wafers in a fixture, create a controlled environment and/or remove various types of unwanted material. It is preferable to utilize a closed system where the negative pressure is constantly maintained and the removed material is separated out from the return vacuum flow so that the vacuum line returns to operation free from any contaminants which could otherwise cause problems with the vacuum pump.
Many appropriate vacuum systems are well known and used in the art, where such systems may be used in either a “dry” vacuum environment or a “wet” vacuum environment. A common problem with all systems, however, is the need to periodically clean the vacuum removal system to eliminate the particulate matter that has accumulated over time. In systems utilizing a separator as a holding tank for the particulate, the separator itself needs to be periodically cleaned, or the vacuum efficiency will begin to decrease and/or some of the particulate matter will pass through the separator and may re-enter the system.
Such periodic cleaning has previously been done by so-called “backflow” methods where a blast of pressure is directed in a reverse direction to unclog dry separators of any particulate matter. Such a system when used with a dry-type separator causes unnecessary mess due to particles or contaminants being blown out of the device into the environment or into a special receptacle. Such a system will still clog after a period of time and requires a manual teardown and reassembly of the separator to restore the proper vacuum flow through the system. Wet separators also require periodic shutdown of the system to drain and clean the separator and then replenish the separator material.
Thus, it would be desirable to develop a vacuum system that provides automatic, periodic cleaning of the accumulating waste in such a manner that the system does not need to be shut down, manually cleaned and then re-charged.